Microwave rock-breaking drilling device

ABSTRACT

A microwave rock-breaking drilling device includes an integrated drill bit assembly, a microwave generating assembly, and a water-jetting and dust-removing assembly, the integrated drill bit assembly comprises a drill bit body, a cutterhead, and a cutting tooth, the cutterhead and the cutting tooth are provided on the drill bit body; the microwave generating assembly comprises a microwave emitting hole, the microwave emitting hole is located on the drill bit body and is communicated with outside; the water-jetting and dust-removing assembly comprises a water jetting hole, the water jetting hole is located on the drill bit body and is communicated with outside.

TECHNICAL FIELD

The disclosure relates to the technical field of drilling, in particular to a microwave rock-breaking drilling device, specifically a drilling device for breaking the rock with the aid of the microwave softening the rock.

BACKGROUND

Drilling is the process of drilling the stratum into a borehole from the ground by using mechanical equipment or manpower. Drilling is usually used in the exploration or development of oil, natural gas and other liquid and gaseous minerals for drilling boreholes, and large-diameter water supply wells and other projects, and drilling is widely used in national economic construction. At present, the commonly used drilling methods are divided into spudder drilling and rotary drilling.

The spudder drilling is also known as percussion drilling wherein the steel wire rope and the drill bit are driven by the power driving device to generate the up-and-down impact to achieve the rock-breaking effect, but this method has the disadvantages of low drilling speed and low efficiency, etc., and cannot adapt to the drilling requirements for deep underground and complex strata. The working principle of rotary drilling is to rotate the drill bit under a certain axial pressure (drilling pressure) to cut or crush the rock into debris, which can substantially improve the drilling efficiency and adapt to various complex conditions of the stratum below the well when compared with the percussion drilling method, and the rotary drilling has become the current mainstream drilling method, but the disadvantages of the rotary drilling are that when the rock hardness is high, the rock breaking speed will largely depend on the hardness of the material of the drill bit itself, and the drilling equipment lacks economic competitiveness due to the cutterhead wear when breaking the rock with high hardness, or the drilling equipment is not fully productive due to the increased rock hardness and the increased amounts of maintenance.

Both of the industry's mainstream drilling methods have bottlenecks that are difficult to break through to a certain extent, which leads to the problems that high drilling costs and low drilling efficiency, etc.

BRIEF SUMMARY

For the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a microwave rock-breaking drilling device, which can complete stirring and injection operations at the same time, and has the advantages of convenient operation, high glue filling efficiency, and the like.

The technical solution of the present disclosure to solve the above technical problem is as follows:

-   -   A microwave rock-breaking drilling device, which comprises:     -   An integrated drill bit assembly, the integrated drill bit         assembly comprises a drill bit body, a cutterhead, and a cutting         tooth, the cutterhead and the cutting tooth are provided on the         drill bit body;     -   A microwave generating assembly, the microwave generating         assembly comprises a microwave emitting hole, the microwave         emitting hole is located on the drill bit body and is         communicated with outside;     -   A water-jetting and dust-removing assembly, the water-jetting         and dust-removing assembly comprises a water jetting hole, the         water jetting hole is located on the drill bit body and is         communicated with the outside.

Compared with the prior art, the beneficial effects of the present technical solution are: On one aspect, when the hard rock drilling is encountered, the microwave generating assembly is used to apply the microwave action to the rock, which changes the rock temperature field to soften the rock, thus to reduce the strength of the rock, reduce the wear of the drill bit, and improve the efficiency of rock breaking. On the other aspect, the effect of the mud, dust, etc. on the microwave emitting hole can be effectively removed by the water-jetting cleaning system, which can reduce the temperature of the drill bit, simultaneously enhance the wave absorption capacity of the rock, increase the effect of the microwave action, improve the efficiency, and reduce the wear of drilling tools.

Further, a cross section of the drill bit body is circular, a plurality of the cutterheads are provided, the plurality of the cutterheads are provided on the drill bit body along a circumference direction at equal intervals, the cutting tooth is provided on the cutterhead;

A plurality of the microwave emitting holes are provided, the plurality of the microwave emitting holes are provided on the drill bit body along the circumference direction at equal intervals, a single microwave emitting hole is located between two adjacent cutterheads;

A plurality of the water jetting hole are provided, the plurality of the water jetting holes are provided on the drill bit body along the circumference direction at equal intervals, a single water jetting hole is located between two adjacent cutterheads.

The beneficial effects of using the above solution are: a plurality of the cutterhead are provided which can improve the drilling efficiency; a plurality of the microwave emitting hole are provided which can improve the softening efficiency; a plurality of the water jetting hole are provided which can improve the cleaning and cooling efficiency.

Further, a distance between the microwave emitting hole and a center of circle of the cross section of the drill bit body is greater than a distance between the water jetting hole and the center of circle of the cross section of the drill bit body.

The beneficial effects of using the above solution are: Briefly, the microwave emitting hole is further away from the center, and the water jetting hole is closer to the center, the structure herein can further improve the cleaning and cooling effect of the water jetting hole.

Further, three cutterheads, three microwave emitting holes, and three water jetting holes are respectively provided.

The beneficial effects of using the above solution are: It has an advantage of reasonable structure, while takes into account the cleaning and cooling effect.

Further, the microwave generating assembly further comprises a microwave source, a waveguide, a circulator, a water load, and a microwave emitting rod;

The microwave source is connected with the circulator through the waveguide, the circulator is connected with the microwave emitting rod through the waveguide, the microwave emitting rod is connected with the microwave emitting hole; the water load is connected with the circulator.

The beneficial effects of using the above solution are: A microwave is emitted through the microwave source, the waveguide, the circulator, the water load, the microwave emitting rod, and other equipment.

Further, the microwave source, the circulator, and the water load are integrated into a microwave generating device, the microwave emitting rod is located on the microwave generating assembly, and the microwave generating device and the microwave emitting rod are connected through the waveguide.

The beneficial effects of using the above solution are: The microwave source, the circulator, and the water load are integrated to form an independent microwave generating device, which makes each part of the present device modular.

Further, the microwave emitting rod between the microwave generating device and the microwave emitting rod comprises an inner conductor, an outer conductor, and a microwave emitting head, the outer conductor is coaxially sleeved on an outer side of the inner conductor, and the microwave emitting head is located at one end farther from the waveguide;

A glass fiber reinforced plastic is arranged between the microwave emitting head and the microwave emitting hole.

The beneficial effects of using the above solution are: The microwave emitting head on the microwave emitting rod is isolated and protected by the glass fiber reinforced plastic.

Further, the water-jetting and dust-removing assembly further comprises a water tank, a water pressure controller, a flow meter, an adapter, and a water pipe;

The water tank is connected with the water pressure controller through the water pipe, the water pressure controller is connected with the flow meter through the water pipe, the flow meter is connected with the adapter through the water pipe, and the adapter is connected with the water jetting hole.

The beneficial effects of using the above solution are: Spray water is provided through the above assemblies to realize the cleaning and cooling, etc. functions.

Further, the water tank, the water pressure controller, the flow meter, and the adapter are integrated into a water-jetting and dust-removing device, and the water-jetting and dust-removing device is connected with the water jetting hole through the water pipe.

The beneficial effects of using the above solution are: The water tank, the water pressure controller, the flow meter, and the adapter are integrated to form an independent water-jetting and dust-removing device, which makes each part of the present device modular.

Further, the integrated drill bit assembly further comprises a drill rod, the drill bit body, the cutterhead, and the cutting tooth are arranged on the drill rod and are located at a lower end of the drill rod; the drill rod is arranged in a drilling well through a drilling support.

The beneficial effects of using the above solution are: The drill bit body, the cutterhead, and the cutting tooth are integrated through the drill rod to form an independent integrated drill bit assembly, which makes each part of the present device modular.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall schematic diagram of a microwave rock-breaking drilling device of the present disclosure.

FIG. 2 is a schematic diagram of the drill bit body in a microwave rock-breaking drilling device of the present disclosure.

FIG. 3 is a top view of the drill bit body in a microwave rock-breaking drilling device of the present disclosure.

FIG. 4 is a cross-sectional view of the drill bit body in a microwave rock-breaking drilling device of the present disclosure.

FIG. 5 is a schematic diagram of the microwave generating assembly in a microwave rock-breaking drilling device of the present disclosure.

FIG. 6 is a schematic diagram of the water-jetting and dust-removing assembly in a microwave rock-breaking drilling device of the present disclosure.

In FIGS. 1-6 , the list of assemblies represented by each label is as follows:

-   -   1. integrated drill bit assembly, 2. microwave generating         assembly, 3. water-jetting and dust-removing assembly, 4.         drilling support;     -   101. drill bit body, 102. cutterhead, 103. cutting tooth, 104.         drill rod;     -   201. microwave emitting hole, 202. microwave source, 203.         waveguide, 204. circulator, 205. water load, 206. microwave         emitting rod, 207. glass fiber reinforced plastic;     -   301. water jetting hole, 302. water tank, 303. water pressure         controller, 304. flow meter, 305, adapter, 306. water pipe.

DETAILED DESCRIPTION OF EMBODIMENTS

In order to make the purposes, technical solutions and advantages of the present disclosure clearer and more explicit, embodiments and drawings are given below to further illustrate the present disclosure. It is to be understood that the embodiments described herein are merely illustrative of the present disclosure and are not intended to be limiting.

In the description of the present disclosure, it is to be understood that the orientation or positional relationships indicated by the terms “center”, “top”, “bottom”, “front”, “rear”, “left”, “right”, etc. are based on orientation or positional relationships shown in the drawings, and are intended only to facilitate and simplify the description of the disclosure, and do not indicate or imply that the device or the assembly referred to must have a particular orientation and be constructed and operated in the particular orientation, therefore are not to be construed as a limitation of the disclosure. Furthermore, the terms “first” and “second” are used for descriptive purposes only, and are not to be construed as indicating or implying the relative importance.

In the description of the disclosure, it is to be noted that, unless otherwise expressly specified and limited, the terms “mount”, “connect”, “connected” are to be understood in a broad sense, for example, the term “connected” may be “fixedly connected”, “detachably connected”, “integrally connected”, “mechanically connected”, “electrically connected”, “directly connected”, “indirectly connected through an intermediary”, or “internally connected of two assemblies”. When an assembly is said to be “fixed to” or “set at” another assembly, the assembly may be directly on the another assembly or there may be other assemblies between the assembly and the another assembly. When an assembly is said to be “connected” to another assembly, the assembly may be directly connected with the another assembly or there may be other assemblies between the assembly and the another assembly. For those ordinary skilled in the art, the specific meaning of the above terms of the present disclosure can be understood in specific conditions.

In the prior art, the two mainstream drilling methods in the industry are the spudder drilling and the rotary drilling, although these two drilling methods can both achieve the basic drilling functions, both of the two drilling methods have bottlenecks that are difficult to break through to a certain extent, which leads to the problems that high drilling costs and low drilling efficiency, etc.

The microwave action generates heat through the intense friction between the molecules of the acted object, so that the overall temperature of the acted object increases, and the heating rate is high so that the rock is softened, and the microwave action also has the advantages of body heating, selective heating, no secondary pollution, etc., so that the microwave action is expected to be used in the engineering rock-breaking field to break the bottleneck of traditional mechanical rock breaking, and has been proved to be technically and economically feasible in the field. Therefore, a drilling principle and device based on microwave rock breaking is proposed, which can reduce the wear of the drill bit to reduce the drilling cost and improve the drilling efficiency. The present disclosure is based on microwave to improve the drilling device in the prior art.

As shown in FIG. 1 , to solve the problems that high drilling costs and low drilling efficiency, etc. in the prior art, the present disclosure provides a microwave rock-breaking drilling device, which comprises an integrated drill bit assembly 1, a microwave generating assembly 2, and a water-jetting and dust-removing assembly 3. In the device, the integrated drill bit assembly 1 mainly undertakes the drilling work, a function of the microwave generating assembly 2 is to provide the microwave to soften the rock, and the water-jetting and dust-removing assembly 3 is used to remove the rock debris produced during the drilling process.

The integrated drill bit assembly 1 comprises a drill bit body 101, a cutterhead 102, and a cutting tooth 103, the cutterhead 102 and the cutting tooth 103 are set on the drill bit body 101; specifically, the drill bit body 101 is a PDC drill body; the microwave generating assembly 2 comprises a microwave emitting hole 201, the microwave emitting hole 201 is located on the drill bit body 101 and is communicated with outside; the water-jetting and dust-removing assembly 3 comprises a water jetting hole 301, the water jetting hole 301 is located on the drill bit body 101 and is communicated with the outside.

The prior art has problems that high wear of drill bit, high drilling costs and low drilling working efficiency, etc., in which one important influencing factor is the excessive strength of the rock. How to reduce the strength of the rock and solve the subsequent effects caused by the high strength of the rock is the key to solve the above problems.

The present disclosure is based on the above technical solution, makes use of the different wave absorption capacity of different minerals, so that the temperature increases rapidly under the action of microwave, and the temperature gradient is generated, and the rock fracture grows and develops, and in high temperature the minerals of the rock are melted or have chemical reactions to achieve the purpose of rock softening. While rotating the drilling rig to break the rock, assisted by the microwave action, by cutting the softened rock after softening the hard rock, the purpose of improving the rate of rock breaking and reducing the mechanical wear can be simultaneously achieved.

On the one aspect, when the hard rock drilling is encountered, using the microwave generating assembly 2 to apply the microwave action to the rock, which changes the rock temperature field to soften the rock, thus reducing the strength of the rock, reducing the wear of the drill bit, and improving the efficiency of rock breaking. On the other aspect, the effect of the mud and dust on the microwave emitting hole 201 can be effectively solved by the water-jetting cleaning system, which can reduce the temperature of the drill bit, and simultaneously enhance the wave absorption capacity of the rock, increase the effect of the microwave action, improve the efficiency and reduce the wear of drilling tools.

As shown in FIG. 2 , a cross section of the drill bit body 101 is circular, a plurality of the cutterhead 102 are provided, the plurality of the cutterheads 102 are provided on the drill bit body 101 along a circumference direction at equal intervals, the cutting tooth 103 is provided on the cutterhead 102; a plurality of the microwave emitting hole 201 are provided, the plurality of the microwave emitting holes 201 are provided on the drill bit body 101 along the circumference direction at equal intervals, a single microwave emitting hole 201 is located between two adjacent cutterheads 102; a plurality of the water jetting hole 301 are provided, the plurality of the water jetting holes 301 are provided on the drill bit body 101 along the circumference direction at equal intervals, a single water jetting hole 301 is located between two adjacent cutterheads 102.

Briefly, the cutterhead 102, the microwave emitting hole 201, and the water jetting hole 301 are all provided on the cross section of the drill bit body 101 in a centrosymmetric manner, with a symmetrical center being a center of the circle of the cross section. Such a structure design is more reasonable, and, compared with a single set-up, a plurality of the cutterhead 102 are provided, which can improve a drilling efficiency; a plurality of the microwave emitting hole 201 are provided, which can improve a softening efficiency; a plurality of the water jetting hole 301 are provided, which can improve a cleaning and cooling efficiency.

As shown in FIG. 3 , a distance between the microwave emitting hole 201 and the center of the circle of the cross section of the drill bit body 101 is greater than a distance between the water jetting hole 301 and the center of the circle of the cross section of the drill bit body 101.

In short, that is, the microwave emitting hole 201 is further away from the center, and the water jetting hole 301 is closer to the center. A circularly smooth connecting line connecting the plurality of the microwave emitting holes 201 can form a closed circle, and similarly, a circularly smooth connecting line connecting the plurality of the water jetting holes 301 can also form a closed circle. The circle formed by the plurality of the microwave emitting holes 201 and the circle formed by the plurality of the water jetting holes 301 are concentric circles, and the circle formed by the plurality of the microwave emitting holes 201 is outside the circle formed by the plurality of the water jetting holes 301.

With such a structure, the water jetting hole 301 is located more centrally, which can further improve the cleaning and cooling effect of the water jetting hole 301. After a high-pressure water column is jetting out from the water jetting hole 301, the column will impact on the rock and then splashes of water appear in all directions, which can better clean out rock debris accumulated at a central axis of the drill bit body 101.

Specifically, three cutterheads 102, three microwave emitting holes 201, and three water jetting holes 301 are respectively provided, which has an advantage of reasonable structure, while taking into account the cleaning and cooling effect.

As shown in FIG. 5 , the microwave generating assembly 2 further comprises a microwave source 202, a waveguide 203, a circulator 204, a water load 205, and a microwave emitting rod 206. The microwave source 202 is connected with the circulator 204 through the waveguide 203, the circulator 204 is connected with the microwave emitting rod 206 through the waveguide 203, the microwave emitting rod 206 is connected with the microwave emitting hole 201; the water load 205 is connected with the circulator 204. A microwave is emitted through the microwave source 202, the waveguide 203, the circulator 204, the water load 205, the microwave emitting rod 206, and other equipment.

The microwave emitting rod 206 between a microwave generating device and the microwave emitting rod 206 comprises an inner conductor, an outer conductor, and a microwave emitting head, the outer conductor is coaxially sleeved on an outer side of the inner conductor, and the microwave emitting head is located at one end farther from the waveguide 203. As shown in FIG. 4 , a glass fiber reinforced plastic 207 is arranged between the microwave emitting head and the microwave emitting hole 201, and the glass fiber reinforced plastic 207 is a quartz structure. The microwave emitting head on the microwave emitting rod 206 is isolated and protected by the glass fiber reinforced plastic 207; at the same time, the quartz material has wave-transmitting characteristics to ensure the effectiveness of microwave emitting.

As shown in FIG. 6 , the water-jetting and dust-removing assembly 3 further comprises a water tank 302, a water pressure controller 303, a flow meter 304, an adapter 305, and a water pipe 306; the water tank 302 is connected with the water pressure controller 303 through the water pipe 306, the water pressure controller 303 is connected with the flow meter 304 through the water pipe 306, the flow meter 304 is connected with the adapter 305 through the water pipe 306, and the adapter 305 is connected with the water jetting hole 301. A jetty high-pressure water column is provided through the above assemblies to realize the cleaning function, cooling function, etc.

The integrated drill bit assembly 1, the microwave generating assembly 2, and the water-jetting and dust-removing assembly 3 in the present device are all modular.

In combination with FIG. 1 and FIG. 5 , the microwave source 202, the circulator 204, and the water load 205 are integrated into the microwave generating device, the microwave emitting rod 206 is located on the microwave generating assembly 2, and the microwave generating device and the microwave emitting rod 206 are connected through the waveguide 203. The microwave source 202, the circulator 204, and the water load 205 are integrated to form an independent microwave generating device, which makes each part of the present device modular.

The water tank 302, the water pressure controller 303, the flow meter 304, and the adapter 305 are integrated into a water-jetting and dust-removing device, and the water-jetting and dust-removing device is connected with the water jetting hole 301 through the water pipe 306. The water tank 302, the water pressure controller 303, the flow meter 304, and the adapter 305 are integrated to form an independent water-jetting and dust-removing device, which makes each part of the present device modular.

As shown in FIG. 1 , the integrated drill bit assembly 1 further comprises a drill rod 104, the drill bit body 101, the cutterhead 102, and the cutting tooth 103 are arranged on the drill rod 104 and are located at a lower end of the drill rod 104; the drill rod 104 is arranged in a drilling well through a drilling support 4. The drill bit body 101, the cutterhead 102 and the cutting tooth 103 are integrated through the drill rod 104 to form an independent integrated drill bit assembly 1, which makes each part of the present device modular.

The microwave rock-breaking drilling device in the present disclosure comprises the integrated drill bit assembly 1, the microwave generating assembly 2, and the water-jetting and dust-removing assembly 3. According to a design principle of PDC drill bit, three cutterheads 102 are uniformly arranged on the drill bit, the microwave emitting hole 201 and the water jetting hole 301 are uniformly arranged in a gap between the cutterheads 102, the waveguide 203 and the water pipe 306 are arranged inside the drill bit, and the microwave generating device and the water-jetting and dust-removing device are connected with the outside of the drill bit through pipes.

The microwave generating assembly 2 comprises an external basic microwave equipment, which is composed of the microwave source 202, the waveguide 203, the circulator 204, the water load 205, and the microwave emitting rod 206. One end of the microwave source 202 is connected with the waveguide 203, and the waveguide 203 transmits the microwave to the water load 205 and the circulator 204, and one end of the circulator 204 is connected with the microwave emitting rod 206 to emit the microwave to act on the rock. The microwave source 202 is composed of a magnetron; the microwave emitting rod 206 is composed of the inner conductor, the outer conductor, and the microwave emitting head. The microwave is led out from the inner conductor and is led out from the microwave emitting head to act on the rock; a material of the microwave emitting head is a wave-transmitting material such as quartz, etc.

The microwave rock-breaking drilling device in the present disclosure can reasonably use its functions according to the hardness of the rock in the drilling area. When the rock hardness is small, the device can directly break the rock by only the mechanical cutting action of the cutterhead 102 of the drill bit; when the rock hardness is large, the microwave generating device can be turned on to soften the hard rock by microwave heating, while the rock breaking drilling operation can be performed together with the mechanical cutting action of the drilling tools; when the rock hardness is extremely large and it is difficult for the drilling tools to break the rock, which seriously affects the working efficiency, the drill bit operation can be stopped, the microwave emitting device can be turned on, and the microwave action can be performed on the hard rock to quickly reduce the mechanical properties of the rock, and then the drill tools can be used to break the rock.

The water-jetting and dust-removing device comprises the water tank 302, the water pressure controller 303, the flow meter 304, and the water pipe 306. The water tank 302 is connected with the water pressure controller 303 through the water pipe 306, and the water pressure controller 303 is connected with the flow meter 304 through the water pipe 306, a water flow pressure and a flow can be controlled through an indication display of the flow meter 304. When a dust is massive or a temperature of an action surface is high, the water-jetting and dust-removing device can be turned on to remove dust and reduce temperature, at the same time, an ability of absorbing wave of rock can be enhanced and an effect of microwave action can be increased.

In summary, the present disclosure provides a microwave rock-breaking drilling device, which comprises the integrated drill bit assembly 1, the microwave generating device, and the water-jetting and dust-removing device; the microwave generating device is mainly composed of the microwave source 202, the waveguide 203, the water load 205, the circulator 204, and the microwave emitting rod 206. The microwave generated by the microwave generating device is used to act on the hard rock, which changes the mechanical properties of the rock, and plays the role of softening the rock and assisting rock breaking; the water-jetting and dust-removing device is composed of the water tank 302, the water pressure controller 303, the flow meter 304, and the water pipe 306. The water-jetting and dust-removing device has the functions of removing dust and cooling, enhancing the wave absorption ability of the rock, and increasing the effect of the microwave action. In the process of deep rock drilling and crushing, due to the high hardness of the rock, it is easy to cause serious wear of the drill bit blades, thus reducing the operation efficiency and increasing the drilling costs. Therefore, it is urgent to upgrade and reform the traditional drilling equipment. By introducing a new type of the microwave-assisted rock breaking device, using the advantages of the body heating, no heat transfer medium, fast heating, and high efficiency of the microwave action, the strength of the rock is weakened when the device acts on the hard rock, which can greatly improve the rock breaking efficiency, reduce the equipment wear, and reduce the drilling costs.

It is to be understood that the present disclosure is not limited to the embodiments described above. Modifications and variations may be resorted to in light of the above teachings by those skilled in the art, all these modifications and variations should be considered as falling within the scope of the appended claims. 

1. A microwave rock-breaking drilling device, wherein comprising: an integrated drill bit assembly, the integrated drill bit assembly comprises a drill bit body, a cutterhead, and a cutting tooth, the cutterhead and the cutting tooth are provided on the drill bit body; a microwave generating assembly, the microwave generating assembly comprises a microwave emitting hole, the microwave emitting hole is located on the drill bit body and is communicated with outside; a water-jetting and dust-removing assembly, the water-jetting and dust-removing assembly comprises a water jetting hole, the water jetting hole is located on the drill bit body and is communicated with the outside.
 2. The microwave rock-breaking drilling device according to claim 1, wherein a cross section of the drill bit body is circular, a plurality of the cutterhead are provided, the plurality of the cutterheads are provided on the drill bit body along a circumference direction at equal intervals, the cutting tooth is provided on the cutterhead; a plurality of the microwave emitting hole are provided, the plurality of the microwave emitting holes are provided on the drill bit body along the circumference direction at equal intervals, a single microwave emitting hole is located between two adjacent cutterheads; a plurality of the water jetting hole are provided, the plurality of the water jetting holes are provided on the drill bit body along the circumference direction at equal intervals, a single water jetting hole is located between two adjacent cutterheads.
 3. The microwave rock-breaking drilling device according to claim 2, wherein a distance between the microwave emitting hole and a center of circle of the cross section of the drill bit body is greater than a distance between the water jetting hole and the center of circle of the cross section of the drill bit body.
 4. The microwave rock-breaking drilling device according to claim 2, wherein three cutterheads, three microwave emitting holes, and three water jetting holes are respectively provided.
 5. The microwave rock-breaking drilling device according to claim 1, wherein the microwave generating assembly further comprises a microwave source, a waveguide, a circulator, a water load, and a microwave emitting rod; the microwave source is connected with the circulator through the waveguide, the circulator is connected with the microwave emitting rod through the waveguide, the microwave emitting rod is connected with the microwave emitting hole; the water load is connected with the circulator.
 6. The microwave rock-breaking drilling device according to claim 5, wherein the microwave source, the circulator, and the water load are integrated into a microwave generating device, the microwave emitting rod is located on the microwave generating assembly, and the microwave generating device and the microwave emitting rod are connected through the waveguide.
 7. The microwave rock-breaking drilling device according to claim 5, wherein the microwave emitting rod between the microwave generating device and the microwave emitting rod comprises an inner conductor, an outer conductor, and a microwave emitting head, the outer conductor is coaxially sleeved on an outer side of the inner conductor, and the microwave emitting head is located at one end farther from the waveguide; a glass fiber reinforced plastic is arranged between the microwave emitting head and the microwave emitting hole.
 8. The microwave rock-breaking drilling device according to claim 1, wherein the water jetting and dust-removing assembly further comprises a water tank, a water pressure controller, a flow meter, an adapter, and a water pipe; the water tank is connected with the water pressure controller through the water pipe, the water pressure controller is connected with the flow meter through the water pipe, the flow meter is connected with the adapter through the water pipe, and the adapter is connected with the water jetting hole.
 9. The microwave rock-breaking drilling device according to claim 8, wherein the water tank, the water pressure controller, the flow meter, and the adapter are integrated into a water-jetting and dust-removing device, and the water-jetting and dust-removing device is connected with the water jetting hole through the water pipe.
 10. The microwave rock-breaking drilling device according to claim 1, wherein the integrated drill bit assembly further comprises a drill rod; the drill bit body, the cutterhead, and the cutting tooth are arranged on the drill rod and are located at a lower end of the drill rod; the drill rod is arranged in a drilling well through a drilling support. 